Sizes for 11 and 12 year olds

Clothes, shoes, bike, scooter, helmet and bedtime sizes for 11 and 12 year olds, all on one page and taken from UK retailers' own charts.

Checked against UK retailer charts on 18 October 2026.

Clothes

Usually 11–12 years (cut for up to 152 cm at Boden)

Shoes

Typically around UK 2.5 to 4, but measure their feet

Bike

24" or 26" wheels

Bike helmet

Juniors size, about 52–59 cm head circumference

Duvet

4.5–9 tog depending on season

School uniform

Chest about 32", waist about 28"

Clothes

UK shops label children's clothes by age but cut them to a height. A label like "11–12 years" fits a child from their 11th birthday up to their 12th, so an 11 year old usually wears 11–12 years and a 12 year old 12–13 years. Boden prints the maximum height for each label:

John Lewis uses single-age labels. Its "11 years" size is cut for the height a child reaches at 11, which is the same as Boden's "10–11". That is why one shop's 11 feels small next to another's 11–12.

If they're between sizes, go by height first, then chest for tops and waist for bottoms. More on this in kids’ clothes sizes by height. Moving into adult sizes? See age 13–16 in women’s and men’s sizes.

Shoes

Two UK shoe shops publish an "average size by age". They don't quite agree, so you get a range:

Feet vary more than height does, so measure heel to longest toe in centimetres and use the kids’ shoe size chart by foot length. Buying a European brand? Use the EU to UK shoe size converter.

Bike

At 11–12 it is 24" or 26". Trek lists 26" (or an XS adult frame) for 11–13 years and 146–160 cm; Raleigh sizes 26" for 135–150 cm. Past that, children move on to adult frame sizes.

Cycling UK's rule of thumb: the wheel diameter in inches should be no bigger than the child's inside leg in inches. Full tables in the kids’ bike size chart.

Scooter

A Maxi-size three-wheeler can still fit, but Micro gives about 58–60 inches (roughly 147–152 cm) as the Maxi’s top height, so most 11–12 year olds move to a two-wheel scooter with an adjustable bar. Whatever the brand, the handlebar should sit somewhere between belly button and mid-chest. See scooter size by age.

Bike helmet

Halfords' guide puts 11–12 year olds in its Juniors size (7+ years), 52–59 cm. Helmets are sized by head circumference, not age, so measure about two finger-widths above the eyebrows. Fit checks are in the helmet size guide.

Bed and duvet

Dunelm suggests 4.5–9 tog for children over three, depending on the season: about 7.5 tog in winter and 2.5–4 tog in summer. A single bed takes a 135 × 200 cm duvet.

More detail in what tog duvet for a child. Pyjamas follow the same age labels as clothes: see kids’ pyjama sizes.

School uniform

Uniform is often sold in inches. Your School Uniform's chart puts the 11/12 yrs age band at:

Full chart and how to measure: school uniform sizes explained.